http://www.noaanews.noaa.gov/stories2016/010616-remains-of-lost-1800s-whaling-fleet-discovered-off-alaskas-arctic-coast.html
I thought it would be interesting to see if the 20th Century Reanalysis (which actually extends back to 1851) shows any hint of unusual weather conditions that could have created unusual pack ice close to the Chukchi Sea coast that September. A Wikipedia article claims that "a stationary high, parked over northeast Siberia, reversed the normal wind pattern and pushed the pack ice toward the Alaskan coast"; I haven't yet examined other sources to see if there is good evidence for this, but it stands to reason that something like this probably happened.
The series of maps below shows the 20th Century Reanalysis sea-level pressure anomaly (departure from normal) for 4 consecutive weeks beginning with August 18-24, 1871. The reanalysis shows lower than normal pressure in the Bering Sea, and a tendency for high pressure over Alaska - especially in the first week - but there is no evidence of a pressure pattern that would tend to drive ice into the coast near Wainwright.
The maps below show the 1000mb vector wind anomaly, which is the vector wind's departure from normal. Again there is no evidence of unusual winds directed towards the Alaskan coast, and in fact the 1st and 4th weeks show the very reverse. Unfortunately all this means is that the 20th Century Reanalysis doesn't appear to explain how the ice conditions became so severe; the reanalysis could be wrong, or there might be another explanation for the ice. Given the presumably very sparse observational data back in 1871, it seems difficult to imagine that the reanalysis could have any real accuracy for this part of the world back then; but it was worth a look, I think.
«soapbox» I personally wouldn't put much stock into a reanalysis of 1871 weather. Today we can't go much beyond 1 week without significant errors and this is with a significant amount of observation data. How many weather stations existed in Siberia and Alaska in the 1870's? So why should be trust a weather model based on such scant data? I think that the model is choosing a best fit that is ultimately random. «/soapbox»
ReplyDeleteStill, it's cool that they found a shipwreck from so long ago. Interesting how such misfortune decimated the American whaling industry - probably for a good thing.
I don't disagree Eric, and I wouldn't trust it at all. But I thought it was worth a quick look to see if the model showed any hints of what might have happened.
DeleteIn the much better covered Atlantic the first three years of the reaanalysis are really bad. Most major storm events are entirely missing - for some reason or another there is a marked skill increase in 1874 - and further after 1882, but there are very annoying biases in the Atlantic arctic all the way to the 1920s. I don't know about the skill in the much more data sparse Alaska area. It is useful to take a look at the ensemble spread that goes with the analysis - it is very large in Alaska during the early years compared to the Atlantic. Even so - the analysis is a sort of a miracle and later versions will be better still.
ReplyDeleteThanks for the interesting remarks, Trausti. I agree the ensemble spread should be very useful. Version 2c of the reanalysis goes back to 1851 and uses additional observations, so it might be somewhat better than the version which started in 1871.
DeleteI hope so - I contributed with observations from Iceland for this earliest period - but I have still not done any comparison within the new 2c version.
DeleteInteresting historical event and analysis. Surely some of the ship logs remain, as well as weather observations pertaining to that time.
ReplyDeleteThis book about it all might have more information and observations:
http://www.amazon.com/Oil-Ice-Disaster-Americas-Whaling/dp/0143118366
As far as the propriety of the industry...yet again demand for product motivated the efforts of that era which led to world-wide maritime exploration. Today not so much, yet some cling to and claim cultural needs. Not on my list of favorites and I'll leave it at that.
Gary